The scene was famously filmed the day after the movie premiered so that it could be hastily added to the movie in time for the wide release, and sees The Avengers taking a well-deserved break after the Battle of New York, following up on Tony's earlier suggestion that they all go and try some shawarma.

It may have looked a little odd that Captain America was the only character not eating shawarma in the scene, but the simple explanation is that Evans had a massive facial prosthetic in place in order to cover up the beard that he had grown for his role in Snowpiercer.

The prosthetic just about works when Evans has his hand covering most of it, but without it, well... you can see for yourself.

You can clearly see the prosthetic Chris Evans had to wear to cover up his facial hair here. Marvel

Speaking in the Marvel Directors' Roundtable, a special feature that will accompany the upcoming Blu-ray release of Avengers: Infinity War, Joss Whedon recalls the impromptu decision to add the scene, and how they dealt with the problem of covering up Evans' beard.

"It was during... While we were doing press after the premiere at the hotel. There was a shawarma place, like, three blocks away. [Kevin Feige] got everybody in there. Evans had a beard. So they put, like... It looked like the Warren Beatty Dick Tracy, like, giant jaw on him, and he just sort of hid it like this [puts his right-hand over his jaw]."

Evans wasn't the only actor who had to hide a physical transformation for this hastily-added scene. Chris Hemsworth had lost all of his Thor bulk in order to slim down for Ron Howard's In The Heart of the Sea, so his costume no longer fit. In order to hide this, he had to hunch down inside the suit, with his wig hiding the gap between his neck and the Thor armor.

EW spoke to the cast of The Avengers the day after the filming of this scene back in 2012, and apparently Evans' make-up was the source of a great many jokes - mostly from Robert Downey Jr., whose cracks includes "Chris, why the long face?" and an Elephant Man-style imitation where he mumbled, "Hey guys, I am not an animal." According to the other actors, the prosthetic effectively glued Evans' mouth shut, so he couldn't talk or eat. No wonder he looks so miserable.

Avengers: Infinity War is now available on Digital HD, and will release on DVD and Blu-ray on August 14.